PHYSICAL AND LITERARY. 189 



the lime, and faturates a fmall portion of it, 

 which then becomes again incapable of diffo- 

 lution, but part of the remaining flaked lime 

 is diflblved and compofes lime-water. 



If this fluid be expofed to the open air, 

 the particles of quick-lime which are nearefl: 

 the furface gradually attrad the particles of 

 fixed air which float in the atmofphere. But 

 at the fame time that a particle of lime is thus 

 Saturated with air, it is alfo refl:ored to its 

 native flate of mildnefs and infolubility j and 

 as the whole of this change muft happen at 

 the furface, the whole of the lime is fuc^ 

 eefllvely collefted there under its original 

 form of an inflpid calcarious earth, called the' 

 cream or crufl:s of lime-water. 



When quick-lime itfelf is expofed to the 

 open air, it abforbs the particles of water 

 and of fixed' air which come within its 

 fphere of attraftion, as it meets with the firfl; 

 of thefe in greatefl: plenty, the greatefl: part 

 of it afTumes the form of flaked lime ; the 

 reft is refliored to its original fl:ate ; and if it 

 be expofed for a fuflicient length of time, the 

 whole of it is gradually faturated with air, to 

 which the water as gradually yields its place. 



We 



